Physics Letters B最新文献

{"title":"Equivalence of 1-loop RG flows in 4d Chern-Simons and integrable 2d sigma-models","authors":"Nat Levine","doi":"10.1016/j.physletb.2025.139325","DOIUrl":"10.1016/j.physletb.2025.139325","url":null,"abstract":"<div><div>We argue for the matching of 1-loop divergences between 4d Chern-Simons theory with Disorder defects and the corresponding integrable 2d <em>σ</em>-models of non-ultralocal type. Starting from the 4d path integral, we show under general assumptions that the 1-loop divergences localise to the 2d defects. They match the ‘universal’ formulae developed in [<span><span>arXiv:2209.05502</span><svg><path></path></svg></span>] for the 1-loop RG flows of integrable 2d <em>σ</em>-models. Our argument uses an alternate path integral representation for the 1-loop effective action and the known classical equivalence between the 4d and 2d theories.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139325"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prospects for measuring neutrino mass with 21-cm forest","authors":"Yue Shao ,&nbsp;Guo-Hong Du ,&nbsp;Tian-Nuo Li ,&nbsp;Xin Zhang","doi":"10.1016/j.physletb.2025.139342","DOIUrl":"10.1016/j.physletb.2025.139342","url":null,"abstract":"<div><div>Both particle physics experiments and cosmological observations have been used to explore neutrino properties. Cosmological researches of neutrinos often rely on the early-universe cosmic microwave background observations or other late-universe probes, which mostly focus on large-scale structures. We introduce a distinct probe, the 21-cm forest, that differs from other probes in both time and scale. Actually, the 21-cm forest is a unique tool for studying small-scale structures in the early universe. Below the free-streaming scale, massive neutrinos suppress the matter power spectrum, influencing small-scale fluctuations in the distribution of matter. The one-dimensional (1D) power spectrum of the 21-cm forest can track these fluctuations across different scales, similar to the matter power spectrum, providing an effective method to constrain neutrino mass. Although heating effects in the early universe can also impact the 1D power spectrum of the 21-cm forest, we assess the potential of the 21-cm forest as a tool for measuring neutrino mass, given that the temperature of the intergalactic medium can be constrained using other methods within a certain range. In the ideal scenario, the 21-cm forest observation will have the ability to constrain the total neutrino mass to around 0.1 eV. With the accumulation of observational data and advancements in observational technology, the 21-cm forest holds great promise as an emerging and potent tool for measuring neutrino mass.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139342"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A representation transformation of parametric Feynman integrals","authors":"Wen Chen","doi":"10.1016/j.physletb.2025.139340","DOIUrl":"10.1016/j.physletb.2025.139340","url":null,"abstract":"<div><div>A transformation on homogeneous polynomials is proposed, which is further applied to parametric Feynman integrals. The two representations related through this transformation are dual to each other. It naturally leads to dualities of Landau equations and linear integral relations between the two representations. For integrals with momentum-space correspondences, the dual representation is equivalent to the Baikov representation.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139340"},"PeriodicalIF":4.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landscape of QCD vacuum","authors":"George Savvidy","doi":"10.1016/j.physletb.2025.139337","DOIUrl":"10.1016/j.physletb.2025.139337","url":null,"abstract":"<div><div>We found new solutions of the sourceless Yang-Mills equation describing the superposition of chromomagnetic vortices of oppositely oriented magnetic fluxes. These gauge field configurations have constant energy densities and are separated by potential barriers forming a complicated landscape. It is suggested that the solutions describe the condensate of chromomagnetic vortices and represent a dual analog of the Cooper pairs condensate in a superconductor. In the presence of an Abelian field and in a particular limit the solutions reduce to flat connections of zero energy density and are forming a complicated potential landscape of the QCD vacuum. A possible tunnelling transition between these superfluxon flat configurations and the flat configurations with non-vanishing Chern-Pontryagin index will wash out the CP violating <em>θ</em> angle to zero, dynamically restoring CP symmetry.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139337"},"PeriodicalIF":4.3,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimate of virtual photon polarization due to the intense magnetic field in Pb-Pb collisions at the LHC energies","authors":"Kento Kimura ,&nbsp;Nicholas J. Benoit ,&nbsp;Ken-Ichi Ishikawa ,&nbsp;Chiho Nonaka ,&nbsp;Kenta Shigaki","doi":"10.1016/j.physletb.2025.139327","DOIUrl":"10.1016/j.physletb.2025.139327","url":null,"abstract":"<div><div>We present the first numerical calculation of the virtual photon polarization and assess the feasibility of measuring the polarization via the anisotropic decay <span><math><msup><mrow><mi>γ</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>→</mo><mi>μ</mi><mi>μ</mi></math></span> using the LHC-ALICE detector. In presence of intense magnetic fields generated in high-energy non-central heavy-ion collisions that exceed the critical magnetic field intensity of quantum electrodynamics (QED), prompt virtual photons are predicted to decay anisotropically into lepton pairs, which we call virtual photon polarization. Using a relativistic resistive magnetohydrodynamics model, we computed the time evolution of the magnetic field and used these results to estimate the averaged polarization by calculating the vacuum polarization under the influence of the magnetic field at specific times. The estimated polarization deviates from zero with a statistical significance of 0.07<em>σ</em> with the data statistics collected from 2010 to 2011 and 0.15<em>σ</em> with the one from 2015 to 2018. It is understandable that the magnetic field could not be detected through polarization due to low statistical significance. With the data collecting the ongoing ALICE run from 2023 to 2026, the statistics dramatically increase by the upgraded LHC and the new data processing system. Thereby we expect that the statistical significance could reach <span><math><mo>∼</mo><mn>1.7</mn><mi>σ</mi></math></span>, resulting in a promising probe for detecting the intense magnetic fields.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139327"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Axion effects on gamma-ray spectral irregularities. II: Implications of EBL absorption","authors":"Hai-Jun Li ,&nbsp;Wei Chao ,&nbsp;Xiu-Hui Tan ,&nbsp;Yu-Feng Zhou","doi":"10.1016/j.physletb.2025.139334","DOIUrl":"10.1016/j.physletb.2025.139334","url":null,"abstract":"<div><div>The extragalactic background light (EBL) plays a crucial role in the propagation of high-energy particles throughout the Universe. In this work, we explore the impact of the EBL absorption effect on photon to axionlike particle (ALP) conversions from the very-high-energy gamma-ray spectral irregularities. For our purpose, we select four BL Lac blazars: Markarian<!--> <!-->501, 1ES<!--> <!-->0229+200, PKS<!--> <!-->0301-243, and PKS<!--> <!-->0447-439 for analysis. Their redshifts range from approximately 0.03 to 0.34. We first discuss the EBL absorption effect on the gamma-ray spectral energy distributions (SEDs) using three common EBL spectral models: Finke-10, Franceschini-17, and Saldana-Lopez-21. Then we consider the photon-ALP conversions in astrophysical magnetic fields. The best-fit chi-square distributions of these EBL models under the ALP assumption in the ALP parameter <span><math><mo>{</mo><msub><mrow><mi>m</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>,</mo><msub><mrow><mi>g</mi></mrow><mrow><mi>a</mi><mi>γ</mi></mrow></msub><mo>}</mo></math></span> plane are provided, showing similar distributions. For comparison, we define a new delta chi-square, <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>d</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>, to quantify the difference in chi-square values. The distributions of <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>d</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> and the gamma-ray SEDs corresponding to the maximum delta chi-square, <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>d</mi><mo>,</mo><mrow><mi>max</mi></mrow></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>, are also presented for comparison. Our results indicate that the influence of these different EBL spectral models is non-dominant at the low-redshift gamma-ray axionscope. In these cases, choosing the latest EBL model, Saldana-Lopez-21, is sufficient. However, as the redshift of the sources increases, this influence becomes more significant.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139334"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N=2 superconformal gravitino in harmonic superspace","authors":"Evgeny Ivanov ,&nbsp;Nikita Zaigraev","doi":"10.1016/j.physletb.2025.139333","DOIUrl":"10.1016/j.physletb.2025.139333","url":null,"abstract":"<div><div>We present the harmonic superspace formulation of <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> gravitino multiplet, the simplest <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> half-integer spin gauge supermultiplet. It is shown that, quite similar to other <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> gauge multiplets, the gravitino supermultiplet is described by unconstrained analytic prepotentials <span><math><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo><mo>+</mo><mi>α</mi></mrow></msup></math></span> and <span><math><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo><mo>+</mo><mo>+</mo></mrow></msup></math></span> which contain a conformal gravitino in the Wess-Zumino gauge. The analytic prepotentials naturally come out from the study of <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> supercurrents associated with hidden symmetries of <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> vector-hypermultiplet system. We construct the covariant <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> superfield strengths and the invariant <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> superfield actions and sketch their component contents. We observe that, at cost of introducing new auxiliary coordinates <span><math><msup><mrow><mi>Ψ</mi></mrow><mrow><mi>α</mi></mrow></msup></math></span> and <span><math><msup><mrow><mi>ω</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span>, the gravitino analytic prepotentials acquire a nice geometric interpretation as extra vielbeins of the covariant harmonic derivative <span><math><msup><mrow><mi>D</mi></mrow><mrow><mo>+</mo><mo>+</mo></mrow></msup></math></span>. We speculate on a possible origin of the additional coordinates, including their relationship with <span><math><mi>N</mi><mo>=</mo><mn>2</mn></math></span> supertwistors.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139333"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spontaneous CP violation, sterile neutrino dark matter and leptogenesis","authors":"Yanjin Jiang,&nbsp;Norimi Yokozaki","doi":"10.1016/j.physletb.2025.139331","DOIUrl":"10.1016/j.physletb.2025.139331","url":null,"abstract":"<div><div>We constructed a model for spontaneous CP symmetry breaking in five-dimensional space-time that has a potential to solve the strong CP problem. To explain the nature of dark matter and the baryon asymmetry of the universe, three right-handed neutrinos and <span><math><mi>U</mi><msub><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow><mrow><mi>B</mi><mo>−</mo><mi>L</mi></mrow></msub></math></span> gauge interaction are introduced in the bulk, in addition to the field contents of the Bento-Branco-Parada model. The wave-function profiles in the fifth dimension can suppress dangerous operators allowed by symmetries, and the scale of spontaneous CP symmetry breaking can be sufficiently large to be consistent with thermal leptogenesis. In this model, the lightest right-handed neutrino serves as dark matter with a mass of <span><math><mi>O</mi><mo>(</mo><mn>10</mn><mo>)</mo></math></span> keV. This small mass and the necessarily small mixing are explained by the exponentially localized wave-function in the fifth dimension due to a bulk mass term. The correct relic abundance is achieved thanks to the <span><math><mi>U</mi><msub><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow><mrow><mi>B</mi><mo>−</mo><mi>L</mi></mrow></msub></math></span> gauge interaction. The other heavy right-handed neutrinos explain the baryon asymmetry of the universe through leptogenesis, with the required CP violating phases generated by interactions involving heavy leptons.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139331"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exact solution to standard model hydrodynamic cosmological perturbation theory and its implications for acoustic oscillations","authors":"Philip D. Mannheim","doi":"10.1016/j.physletb.2025.139336","DOIUrl":"10.1016/j.physletb.2025.139336","url":null,"abstract":"<div><div>We present an exact solution to standard model cosmological perturbation theory in a matter-dominated, adiabatic, hydrodynamic era. The solution is in the form of hypergeometric functions. While such functions can oscillate with the sound velocity, they can only do so at high frequency. There is thus a maximum wavelength to these oscillations, with this maximum wavelength serving to provide a horizon for acoustic oscillations.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139336"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Baryon number violating hydrogen decay","authors":"Wei-Qi Fan ,&nbsp;Yi Liao ,&nbsp;Xiao-Dong Ma ,&nbsp;Hao-Lin Wang","doi":"10.1016/j.physletb.2025.139335","DOIUrl":"10.1016/j.physletb.2025.139335","url":null,"abstract":"<div><div>Most studies on baryon number violating (BNV) processes in the literature focus on free or bound nucleons in nuclei, with limited attention given to the decay of bound atoms. Given that hydrogen is the most abundant atom in the universe, it is particularly intriguing to investigate the decay of hydrogen atom as a means to probe BNV interactions. In this study, for the first time, we employ a robust effective field theory (EFT) approach to estimate the decay widths of two-body decays of hydrogen atom into standard model particles, by utilizing the constraints on the EFT cutoff scale derived from conventional nucleon decay processes. We integrate low energy effective field theory (LEFT), chiral perturbation theory (ChPT), and standard model effective field theory (SMEFT) to formulate the decay widths in terms of the LEFT and SMEFT Wilson coefficients (WCs), respectively. By applying the bounds on the WCs from conventional nucleon decays, we provide a conservative estimate on hydrogen BNV decays. Our findings indicate that the bounds on the inverse partial widths of all dominant two-body decays exceed 10⁴⁴ years. Among these modes, the least constrained diphoton decay <span><math><mi>H</mi><mo>→</mo><mi>γ</mi><mi>γ</mi></math></span> might be astrophysically interesting, although the monochromatic photon signal from our Sun is difficult to detect with current near-Earth telescopes.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139335"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}